A vast cavern is the stage for tests to find the 'God particle'

The Times ^

[AndrewC]

I'm pretty sure they mean that the region AT THE TIME OF INFLATION must TODAY be at least the size of the observable Universe, which is exactly what 13 billion years of normal non-inflationary expansion does to to the Universe.

You didn't read the link. -- "at least" means something.

How much inflation do we need to solve the horizon and flatness problems? We will see that sensible models of inflation tend to place the inflationary epoch at a time when the temperature of the universe was typical of Grand Unification,

(75)

so that the horizon size, or size of a causal region, was about

(76)

In order for inflation to solve the horizon problem, this causal region must be blown up to at least the size of the observable universe today, ⁽⁸⁾

(77)

So that the scale factor must increase by about

(78)

or somewhere around a factor of e⁵⁵. Here the extra factor a(t_i) / a(t₀) accounts for the expansion between the end of inflation T_i ~ 10¹⁵ GeV and today, T₀ ~ 10^-4 eV. This is the minimum amount of inflation required to solve the horizon problem, and inflation can in fact go on for much longer.

It doesn't take but one more 10²⁴ inflation to make up for much of the 10²⁸ expansion. I take it that much longer means several periods longer.

My point has been clearly a problem with any matter being involved in the inflation.

[AndrewC]

Sorry about "you didn't read the link". I read your post and then clicked on the reply button. I took a fair amount of time in forming the reply and didn't see this intervening message, however my answer still applies, barring the "you didn't..." part.

[PatrickHenry]

Inflationary PLACEMARKER

[A. Pole]

Cheap at any price, even £1.5 billion, to get us a little closer to understanding the universe.

Certanly a cheap way to get rid of a planet!
See A black hole ate my planet

[jwalsh07]

So in that sense, you've asked what is technically an ill-formed question; for which there is no answer because the question assumes facts contrary to the theories you are expecting to provide the answer

Really? But if inflation had occurred one unit of time earlier, then t=0 would have happened at t={-1}.

But thats neither here nor there. You tell me I've asked a technically ill-formed question while you expound on a technically ill-formed theory that violated the first law of thermodynamics and every other law during inflation.

You have no idea what dark matter is, it has never been observed and can't be found in our galaxy. Yet it constitutes anywhere from 70 to 90% of the Universe depending on which Cosmologists you listen to.

The singularity came out of nowhere containing nothing except it had to contain at a minimum quanta and vacuum. So apparently something is south of the south pole, no?

[Dataman]

Right Wing Prof is opus'ed and gone?

(He was setting an example.)

ALS and conservababblerJen are still able to delete threads by wandering in, pooping in the punchbowl, and screaming in faces? This really bites bad!

I believe it was you who did the manly deed of pressing the abuse button against a woman and got the thread deleted.

[longshadow]

So the universe is still expanding, right?

Not only expanding, but expanding at an increasing rate!

only now it is either at or below the speed of light? Correct?

Depends upon what two points you chose to measure the expansion. If you choose a point within about 13 billion light years of Earth, we observe sub-luminal expansion, but since BB cosmology predicts the recessional rate (due to expansion) is proportional to distance, anything beyond about 13 billion light years would be moving away so fast that we can't see it... from here. IOW, everything beyond that distance is outside our light horizon, and is undetectable to us.

[Physicist]

IOW, everything beyond that distance is outside our light horizon, and is undetectable to us.

In principle that's true, but in practice the universe becomes opaque before we reach the edge of our Hubble volume. But you're right: the point should not be lost that, according to the observed flatness of the universe, it should be of infinite size in all directions, with all but our tiny, finite corner being geometrically unreachable to us.

[VadeRetro]

I believe it was you who did the manly deed of pressing the abuse button against a woman and got the thread deleted.

I value your opinion on the death of the last two crevo threads about as much as your opinion on transitional fossils. This thread has a real science article up front so I will spare it further discussion of what happened.

[Gargantua]

"Whereas if it were "faith" no amount of evidence would convince us we were wrong."

Amen.

[RightWhale]

You make my case.

Glad to be of service.

[Dataman]

Hey! Look what I happened across. Your home page?

:)

[longshadow]

It doesn't take but one more 10^24 inflation to make up for much of the 10^28 expansion. I take it that much longer means several periods longer.

My point has been clearly a problem with any matter being involved in the inflation.

It may be clear to you, but I'm not even sure what you feel is a problem here. Furthermore, I didn't notice anything in the section of the the website you quoted (which is far more authoratative than anything I can write on this subject) mentioning any "problem."

I suggest you take up your "problem" for Inflationary Cosmology with "physicist," who is vastly more qualified than I am to address whatever it is.

[longshadow]

But you're right: the point should not be lost that, according to the observed flatness of the universe, it should be of infinite size in all directions, with all but our tiny, finite corner being geometrically unreachable to us.

That's what I was getting at.

Correct me if I am wrong, but I believe the correct term to characterize those "unreachable" regions of the Universe is that they are "causally disconnected" from ours, and ours from them.

[AndrewC]

"causally disconnected" from ours, and ours from them.

A fancy term for supernatural.

[AndrewC]

I didn't notice anything in the section of the the website you quoted (which is far more authoratative than anything I can write on this subject) mentioning any "problem."

Relative velocities v > c are allowed in general relativity as long as the observers are sufficiently separated in space.

[longshadow]

"Relative velocities v > c are allowed in general relativity as long as the observers are sufficiently separated in space."

The complete quote is:

Relative velocities v > c are allowed in general relativity as long as the observers are sufficiently separated in space. (7) This mechanism provides a neat way to explain the apparent homogeneity of the universe on scales much larger than the horizon size: a tiny region of the universe, initially in some sort of equilibrium, is "blown up" by accelerated expansion to an enormous and causally disconnected scale.

[emphasis added]

Apparently, the author of the website you are quoting doesn't see this as a "problem," as much as he sees it as a solution.

But as I still have no idea what you see as "the problem," I can't really respond to it. Why not ask "Physicist" to help you out?

[AndrewC]

But as I still have no idea what you see as "the problem,"

I don't know how to explain it other than--->

When the distance between 2 things is increased(or decreased), something has moved. That is, when r₀ != r₁ something has moved.

[Hajman]

Godel's Incompleteness Theorem merely states that, in any "omega-complete" formal system -- in layman's terms, a system of sufficient expressive generality and abstraction to describe its own operations and permit self-reference -- there are demonstrably true statements for which no proof exists within that system. But this is strictly a mathematical phenomenon, based on the rigid mathematical definition of a proof.

You may be correct that Godel's Incompleteness Theorem is for the mathematically (and computer) inclined person, but it's still true that the universe can never be 100% explained.

-The Hajman-

[<1/1,000,000th%]

When the distance between 2 things is increased(or decreased), something has moved. That is, when r0 != r1 something has moved.

I think AndrewC is trying to understand the notion that 2 particles are now farther away, but neither of them moved. We used to just say the space moved, but I'm not sure that helps.

Inflation is one of those things that seems like happened, because it's consistent with known observations, but to me it's a lot like trying to understand the 2nd law of thermo. It requires several attempts with the alcoholic beverage of your choice.